Biology - a science of exception, Biology

BIOLOGY - A SCIENCE OF EXCEPTION -

Some common examples to prove it are -

1.       Embryos of dicot plants have 2 cotyledons but in cuscuta (Dodder plant or amer bel or Akash bel) cotyledons are absent.

2.       Nucleus generally present in all cells except R.B.C. of mammals (in camel & lama present), sieve tubes of phloem of plants.

3.       DNA present in all animal viruses except influenza virus, polio virus, reo virus in which RNA present.

4.       RNA present in all plant viruses except cauliflower mosaic virus in which DNA present.

5.       In human 206 bones present, in human having 6 fingers in one hand 209 bones present.

6.       In birds urinnary bladder absent but present in ostrich.

7.       Kangaroo rat never drinks water in life.

8.       DNA is double strandded but in fx 174 bacteriophage single stranded DNA present.

9.       RNA is single strended but in wound tumour virus & reo virus it is double stranded. 

10.     Sexual reproduction usually occurs at puberty but in Ambyostoma's axolotal larva, it occurs at larval stage. This process is paedeogenesis and stage is neotany.

11.     Blood of all vertebrtes is red but in corcharinus (shark) it is colour less.

12.     Mammals are viviparous while Platypus, Echidna are oviparous & Kangroos or marsupials (having marsupium ponch) are ovo-viviparous.

13.     Fishes usually respire by gills but in Protopterus, Lepidosiren, Ceratodus lungs present (Dipnoi).

14.     Heart of all reptiles is incomplete 4 chambered but in crocodelia 4 chambered.

15.     In pisces heart is 2 chambered but in dipnoi 3 chambered.

16.     Mostly birds fly except ostrich, kiwi & penguine.

17.     Mammals do not fly except bat & lemur.

18.     Usually young ones are produced from zygotes while dron (male) of honey bee are formed from unfertilized egg by parthenogenesis. Dron is not having father but forefather (Nana) is present.

19.     Chromosomes number in diseased human may be 45 or 47.

20.     Femur is largest bone of human body while stapes is smallest bone.

Posted Date: 10/8/2012 4:22:14 AM | Location : United States







Related Discussions:- Biology - a science of exception, Assignment Help, Ask Question on Biology - a science of exception, Get Answer, Expert's Help, Biology - a science of exception Discussions

Write discussion on Biology - a science of exception
Your posts are moderated
Related Questions
what does ICZN stand for

Group Psychotherapy:  Definition  Group psychotherapy  is a treatment of psychological problem in which two or more patients interact in the present of a psychotherapist.

differnce between protonephridia and metanephridia

A woman who is heterozygous for a particular X-linked recessive trait marries a phenotypically normal man. What percentage of their sons will show the recessive phenotype?

Among neonates, IE typically involves the tricuspid valve of structurally normal hearts and is associated with very high mortality rates.  It is likely that many of these episodes

Which of the following best describes why Okazaki fragments are not observed in PCR? A. DNA primase is used for the entire reaction therefore eliminating the production of Okaz

Explain the Cladosporium - Fungi and Yeast? Classification Kingdom - Mycetae Division - Amastigomycota Form - Class - Deauteromycetes Form - Order - Moniliales F

XYY humans are fertile males. XXX humans are fertile females. What do these observations reveal about the mechanisms of sex determination and dosage compensation?

Can the heat capacity of water be considered small or large? What is the biological significance of that characteristic? From thermology it is called that the quantity of exch